Hottinger Baldwin Messtechnik Gmbh

Hottinger Baldwin Measurements Inc.

Hottinger Baldwin Messetechnik Gmbh

Ralf Waegner

Werner Schlachter

Hans-Joachim Gerlach

Ronald Will

Heinz Ronald Will

Reimar Hellwig

Markus Franz

Felix Von Hertling

Hans-J Gerlach

A measuring pick-up or load cell shall be made less sensitive against off-center load applications, if necessary. At least it must be made certain that the off-center load sensitivity is within a permissible tolerance range. For this purpose the sensor body (1A, 1', SB) of the detector (1) to which there is applied at least one pick-up element or strain gage (5), is held for each load application in a different fixed position in a mounting (2) in such a way that, spaced from the clamping position a test load can be applied in a direction deviating from the direction and/or position of the axis of symmetry (CA, AS) of the sensor body (1A, 1', SB). The test loads may be uniform or they may differ for one or more load application points. A respective output signal is measured and correlated to the applied test load. At least one additional test load of the same size is applied in a different load application direction, and the respective output signal is again measured and correlated to the second test load. Then, the output signals are evaluated with reference to a tolerance range (TR) stored in a memory of a control unit (11) to determine whether a tuning of the sensor body is necessary to make the pick-up less sensitive. If such tuning is necessary, at least one tuning is performed. The tuning may be a mechanical material removal from the sensor body and/or as an electrical tuning by resistor adjustments.

Method and apparatus for making load cells less sensitive to off-center

For producing load cells, especially for platform scales in which a beam that is clamped at one end in a bending stiff manner, is loaded at its opposite end, the measuring spring (1) is formed by a section (2) of a blank having a constant cross-section along its length. The section (2) is severed from the blank by parallel cuts so that the cut end surfaces (4) of the measuring spring (1) extend in parallel to each other and at a slant of an angle (.alpha.) to the central plane (3). Hereby the expense for material is reduced.

Load cell

A rod-shaped weighing cell (1) for a vertical compression load sensing having spherically formed and/or plane load application end surfaces (2, 3) has in the center areas (19) or recesses (19) or a cross-bore (4) to which strain gages (9) are attached. The crossbore, or areas, or recesses or is closed at both ends or covered with a metallic cover (7, 8) the edges of which are sealed e.g. welded to the weighing cell body 1A). One cover disk (7) is provided with a screw connector (10) for a lead-through of a cable (11) which is connectable to the strain gages (9). The cover disk is just large enough to enclose and seal the strain gages without enclosing or encircling the entire load cell body.

Pin load cell for weighing

A measuring pick-up or detector shall be made less sensitive against off-center load applications if necessary. At least it must be made certain that the off-center load sensitivity is within a permissible tolerance range. For this purpose the sensor body (1A, 1', SB) of the detector (1) to which there is applied at least one pick-up element or strain gage (5), is held for each load application in a different fixed position in a mounting (2) in such a way that, spaced from the clamping position a test load can be applied in a direction deviating from the direction and/or position of the axis of symmetry (CA, AS) of the sensor body (1A, 1', SB). A respective output signal is measured and correlated to the applied test load. At least one additional test load of the same size is applied in a different load application direction, and the respective output signal is again measured and correlated to the second test load. Then, the output signals are evaluated with reference to a tolerance range (TR) stored in a memory of a control unit (11) to determine whether a tuning of the sensor body is necessary to make the pick-up less sensitive. If such tuning is necessary, at least one tuning is performed. The tuning may be a mechanical material removal from the sensor body and/or as an electrical tuning by resistor adjustments.

Method and apparatus for making load measuring pick-ups less sensitive

The rotation of a rocker pin about the longitudinal pin axis in a rocker pin load cell is limited by a collar (7) directly connected to a pin end and having spaced stop surfaces (11, 12; 11', 12') cooperating with a stop stud (8) mounted in a socket (4 or 3) in which the pin end with its collar (7) is held. The long axis of the stop stud extends in parallel to the pin axis in its normal vertically aligned position.

Rocker pin load cell with a rotation limiter

A precision pressure sensor in the form of a load cell has a mounting ring closed at one end by an end wall which has axially outwardly facing dead-end holes therein to form sensor beams each having an axially outwardly facing plane surface to which strain gages are bonded. The dead-end holes have bottoms forming sensor membranes. Opposite the closed end the mounting ring encloses a cavity forming a sensor space which is closed by a closure plug that simultaneously has a bore for admitting fluid under pressure to be measured into the sensor space. A ring groove in the end wall has approximately radially sloping surfaces which together with the dead-end holes determine the minimum cross-section of the measuring beams. The ring groove also determines the minimum thickness of the sensor membranes.

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Trebur, Germany

Ralf Waegner